Process for preparing dialkyldithiophosphoric acid ester derivatives having two amide groups in the molecule and the insecticidal compounds obtained thereby



PROCESS FOR PREPARING DIALKYLDITHIO- PHOSPHORIC ACID ESTER DERIVATIVES HAV- ING TWO AMIDE GROUPS IN THE MOLECULE AND THE INSECTICIDAL COMPOUNDS OB- TAINED THEREBY Raffaello Fusco, Giuseppe Losco and Mario Periui, Milan, Italy, assignors to Montecatini-Societa Geuerale per llndustria Mineraria e Chimica, a corporation of Italy No Drawing. Application July 10, 1956 Serial No; 596,845

Claims priority, application Italy July 14, 1955 3 Claims. (Cl. 260-268) The present invention relates to a new type of compounds deriving from a diamine, 'whereby amide linkages bind the two basic groups to identical dialkyldithiophosphoryl acetic acid radicals. Moreover, .the invention relates to the process of preparing these compounds and to their use as insecticides.

These compounds may be defined by the structural formula wherein R represents a lower alkyl, R represents hydrogen or may be absent, R" represents an aliphatic chain (such as -CH -CH -CH (CH or, if

R is absent, two aliphatic chains forming with the two nitrogen atoms a ring, such as CHrCHg CHrCg or an aromatic nucleus, such as 40 or a mixed aliphatic-aromatic chain, such as 2,901,481 Patented Aug. 25, 1959 A modification of the process consists in using, instead of said phosphate, the corresponding acid phosphate and abasic compound of the metal which is sufliciently alkaline to neutralize the acid phosphate (for example, Na CO K CO KOH, NaOH, etc.).

The reaction is carried out in the presence ofa solvent for either or both reactants. Water, alcohols, ketones, ethers, esters, dioxane and aromatic hydrocarbons can beused as solvents.

EXAMPLE 1 40 g. pure diethyldithiophosphoric acid dissolved in 200 cc. acetone are neutralized with 12 g. anhydrous sodium carbonate and to the solution thus, obtained 21 g. of bis-ethylenediamide of monochloroacetic acid are added in small quantities while stirring. The mixture is stirred .for 2 hours. After standing overnight, the. mixture is refluxed for 3 hours while stirring, and the solvent is distilled off by heating on a boiling water bath. The residue is cooled, treated with water and.

stirred for half an hour. The mixture is then filtered by suction. 34 g. of a product, M.P. 89-92" C., are obtained. Upon crystallization from methanol, beautiful crystals are obtained, M.P. 103-105 C. The analysis agrees with the formula 41 g. diethyldithiophosphoric acid, dissolved in 170 cc. acetone, are neutralized with 11.6 g. potassium carbonate. The mass is stirred for half an hour and 23.9 g. of bis-piperazide of monochloroacetic acid are added. After standing overnight, the mixture is refluxed for one hour and the acetone is distilled off on a boiling water bath. The residue is cooled and treated with water. An oil is separated which crystallizes upon rubbing the wall of the container. The crystalline precipitate is ground with a Nal-ICO solution and the mass obtained is fil-. tered by suction. 34 g. of a white powder, M.P. -77 C., are obtained. Upon crystallization from 70% methanol, crystals are obtained, M.P. 8889 C.

Theanalysis agrees with the formula Products defined by the herein claimed general formula have proved to possess important insecticidal properties which make them suitable for a practical use in parasite control. 1

The following examples are presented to illustrate these properties:

Musca domestica After topical application, by means of a micro-syringe, of acetone solutions of the compounds under examination to five days old flies, the following average per cent mortalities were obtained after 20 hours:

'ylfly 50 1o 2 0.4

Percent mortality after 20hours Ethylenediamide of 0,0-diethyldlthlophosphorylacetlc acid 16 5 0 After tarsal absorption, by introducing five days old female flies into beakers previously treated with controlled amounts of benzene solutions of the active sub stances under examination, and leaving the flies in contact with these substances for 20 hours, the following mortalities were observed:

Percentg./m. mortality after 20 hours Ethylenediamide of 0,0-diethyldithiophsphorylacctic acid 0. 125 21 Piperazide of 0,0-diethyldithiophosphorylacetic acid 0.125 2 Aphis fabae By spraying a population of aphides, apterous virginoparous females, on bean plants under standardized conditions with suitably formulated aqueous dispersions of the substances under examination, the following average mortalities were obtained after 24 hours:

Percent cone. permortality cent 11.8. after 24 hours Ethylenediamide of 0 O-diethyldithiophosphorylacetic acid 8:? 22 Piperazide of 0,0-diethy1dithiophosphoryl- 0 5 35 acetic acid 7 4 Tetranychus telarius By spraying a mixed population of mites in various stages of growth on bean plants under standardized conditions with suitably formulated aqueous dispersions Spraying of mite eggs gave the following average mortalities:

Percent cone. permortality cent A.S. after 6 days i i 0.5 100 Ethylenediamide of 0,0-d1ethyld1th1ophos- 025 90 phorylacetic acid 125 75 V 0. 063 30 Piperazide of 0O-diethyldithiophosphorylaceticacid -1 3'3 8 -Moreover, the DL was determined by the same technique for the various applications for the ethylene- 'diamine of 0,0-diethyldithiophosphorylacetic acid:

Aphis fabaeDL 95 in percent A.S 0.3 Tetranychus telariusDL 95 in percent A.S 0.015 Eggs of T. telarius-DL 95 in percent A.S 0.3

Determination compounds of this application The acute toxicity per os was determined and compared With that of Parathion by'gastric sounding and administration of solutions of the products under examination in dime'thylacetamide to white mice (size The solvent interference with the toxic phenomena is negligible.

DL 50in mg./kg. Parathion 8.2 Ethylencdiamide of 0,0-diethyldithiophosphorylacetic acid 123.1

We claim: 1. The insecticide of the formula H C H O) PSS CH -CONHCH CH NHCOCH SPS(OC H 2. The insecticide of the formula 3. An insecticide taken from the group consisting of those of the formula:

and those of the formula:

no s CH2CH2 \]|.LSCH:4C ON/ NC OCH2S R0 onto on in which respective formulae R is a number of the group consisting of methyl and ethyl, and X is a bridging group taken from the class consisting of -CH CH CH the phenylene radical C H the mixed aliphatic-aromatic chain s oR References Cited in the file of this patent UNITED STATES PATENTS Cassadaytet a1. Jan. 10, 1950 Hook et al. Feb. 19, 1952 of the acute toxicity per as of one of the' 

3. AN INSECTICIDE TAKEN FROM THE GROUP CONSISTING OF THOSE OF THE FORMULA 